The Medwecki and Nowakowski M.N.5 was an economical Polish trainer aircraft initially aimed at the club market, though there was also some military interest. It performed well but lacked a constructor after

Samolot Samolot (full name: Wielkopolska Wytwórnia Samolotów ''Samolot'' '' S.A.'') was the Polish aerospace manufacturer, located in Poznań and active between 1924 and 1930. It manufactured among others aircraft under the Bartel name. The name ''Samo ...

became insolvent in 1930, so only one was completed.

Design and development

The increasing number of Polish aeroclubs in the early 1930s called for a suitable training aircraft. LOPP, the group that encouraged Polish air-mindedness put out a call for suitable designs, powered by a engine, that would be cheap to buy and to run. Three designs received development contracts, the PZL 5, the Sido S.1 and the M.N.5. The latter was designed by Józef Medwecki and Zygmund Nowakowski, both of whom worked for Samolot. With the company's help, two M.N.5 airframes were built, one for static load testing and the other for flight. The wood-framed M.N.5 was a single bay biplane with stagger and a large interplane gap to ease

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

access. The equal span upper and lower wings were both in two parts with rectangular plans out to blunted tips. They were built around pairs of

spars The United States Coast Guard (USCG) Women's Reserve, also known as the SPARS (SPARS was the acronym for "Semper Paratus—Always Ready"), was the women's branch of the United States Coast Guard Reserve. It was established by the United States ...

and largely covered with

fabric Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...

, together with some

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

. Upper and lower wings were braced together with conventional N-form interplane struts but in addition a long steel tube strut, larger in diameter than the others, ran in the plane of the forward spars from the top of the interplane strut down to the lower spar just outboard of the

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the sur ...

. As well as replacing flying wires, this strut supported the leading edge of the lower wing when the wings were disconnected from the root and folded back alongside the fuselage, hinging on the rear spars. The wing root was strengthened by an inverted V-strut from its spars to the upper fuselage longeron. The upper centre section was formed by an aerofoil section fuel tank, held over the upper fuselage by three pairs of struts, the forward-most leaning rearwards to the forward spar and the others, in parallel, outwards to the rear spars. Only the lower wing was mounted with dihedral; it also carried the M.N.5's full span, narrow

chord Chord may refer to: * Chord (music), an aggregate of musical pitches sounded simultaneously ** Guitar chord a chord played on a guitar, which has a particular tuning * Chord (geometry), a line segment joining two points on a curve * Chord ( ...

ailerons. With wings folded, the M.N.5 was wide. The M.N.5 was powered by a Armstrong Siddeley Genet five-cylinder

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...

enclosed by a Townend ring. The mostly wooden fuselage had four

longeron In engineering, a longeron and stringer is the load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural ...

s connected by frames, though the forward part was reinforced with steel tubes. Its covering, including rounded decking, was plywood. There were two

s in tandem, fitted with dual control. The instructor sat in front under the wing and the student just aft of the trailing edge. Behind the pupil's cockpit there was a third seat under a detachable ply cover. Its curved and slightly pointed

empennage The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...

was steel-framed and fabric-covered with a

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

that extended down to the keel. The

tailplane A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplane ...

's angle of incidence could be adjusted in flight. There were separate

elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

s, each identical to each other and to the rudder, keeping costs down. The M.N.5 had a wide track, divided

undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...

with mainwheels on cranked half-axles hinged from the fuselage underside centreline; a

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...

oleo strut from the stub wing and a

radius arm A radius rod (also called a radius arm, torque arm, torque spring, and torsion bar) is a suspension link intended to control wheel motion in the longitudinal (fore-aft) direction. The link is connected (with a rubber or solid bushing) on one end ...

formed a V-strut on each side. Its short tailskid had a vertical, rubber cord shock absorber. It flew for the first time on 21 August 1932 from Poznań-Ławica. Early testing revealed some stability problems which were overcome by moving the engine forward in a longer nose. The M.N.5 was then flown by both civil and service pilots, who remarked on its good handling and manoeuvrability. The Department of Aeronautics, looking for a replacement for its Hanriots, was enthusiastic and the construction of a second prototype to speed development was proposed. Unfortunately, as Samolot was in the process of liquidation, another builder had to be found. The Ministry proposed PZL who were developing the PZL 5 and showed no interest in helping a competitor, so no more N.M.5s were built.

Operational history

The lone example was bought by the

Vilnius Vilnius ( , ; see also other names) is the capital and largest city of Lithuania, with a population of 592,389 (according to the state register) or 625,107 (according to the municipality of Vilnius). The population of Vilnius's functional urb ...

aeroclub in 1931 and, registered as ''SP-AEH'', served them for many years. It took part in many rallies and competed in regional and national championships.

Specifications

References

{{reflist, refs= {{cite book, title=Polish Aircraft 1893-1939, last=Cynk, first=Jerzy, year=1971, publisher=Putnam Publishing, location=London, isbn=0-370-00085-4, pag
348-380
url-access=registration, url=https://archive.org/details/polishaircraft1800cynk/page/348 Biplanes Single-engined tractor aircraft 1930s Polish civil trainer aircraft